The position of a user equipment (UE), such as a mobile phone, tablet computer, personal media player, or other wireless electronic device can be estimated based on wireless signals transmitted by wireless access points (APs) and/or base stations (BSs) and received by the UE. If the locations of the APs and/or BSs are known (e.g. by the UE or a separate location server), the UE or the location server can estimate the position of the UE by using measurements (e.g. timing or range measurements) obtained by the UE of the wireless signals.
In some scenarios however, the UE may not be within effective range of a sufficient number of APs and/or BSs to enable an accurate position estimation. For example, this may occur in buildings with obstructing features, such as thick concrete walls and floors, that limit the effective signal coverage range of APs and BSs. In other scenarios, the UE may not have effective positioning capabilities and resources, such as a lack of inertial sensors, lack of support for positioning based on signals from APs and BSs, or lack of sufficient battery power to perform positioning on a frequent basis. Exemplary embodiments of the disclosure address these problems, both individually and collectively.